1. Field of the Invention
The present invention relates to a mobile station, and more particularly to a method for processing Video On Demand (VOD) data in a mobile station, which can rapidly process VOD contents in the mobile station connected to a VOD service provider.
2. Description of the Related Art
Recently, as communication technologies have developed, mobile stations have a plurality of supplementary functions as well as the normal communication function. Such supplementary functions include a camera function, a camcorder function, and a multimedia function. Herein, the multimedia function is to reproduce data of various media including voice, text, still pictures, moving pictures, and the like, so users of the mobile stations equipped with multimedia functions can receive VOD services for the various multimedia contents, that is, video data (e.g., ‘VOD data’) such as movies, music videos, and the like, from multimedia providers through a wireless network.
The VOD service provides multimedia contents in a streaming format (in other words, in real-time). The mobile station contains a separate multimedia chip (such as a multimedia processor) besides a control chip (a mobile station modem (MSM), for example) for performing the general control functions of the mobile station so as to more stably process the VOD data.
FIGS. 1A and 1B are views representing VOD protocol stacks of an MSM and a multimedia processor for VOD service in a conventional mobile station, respectively.
The protocol stack for the MSM shown in FIG. 1A includes a physical layer, which is the lowest layer, a Radio Link Protocol (RLP) layer, a Point to Point Protocol (PPP) layer, an Internet Protocol (IP) layer, a Transmission control Protocol/User Datagram Protocol (TCP/UDP) layer, a Socket layer, and a Wireless Application Protocol (WAP) layer, which is the highest layer in the sequence.
That is, such a MSM is connected to the WAP-based Internet by negotiation of the PPP layer.
Also, the protocol stack for the multimedia processor shown in FIG. 1B includes an IP layer, a TCP/UDP layer, a Socket layer, and a real-time transfer protocol/real-time conferencing protocol/real-time streaming protocol/hypertext transfer protocol (RTP/RTCP/RTSP/HTTP) layer.
Such a multimedia processor receives VOD data, which has been received by the MSM through the WAP-based Internet and has been decapsulated from the lowest layer to the PPP layer of VOD data by the MSM, and processes the VOD by decapsulating the VOD data from the IP layer to the RTP/RTCP/RTSP/HTTP layer. Also, data is transmitted to a VOD server, the multimedia processor transmits transmission data to the MSM in a sequence opposite to the received VOD data processing sequence.
In this case, the MSM processes VOD data according to a priority as shown in FIG. 2. In FIG. 2, ‘TASK’ represents a task performed for VOD service by the MSM, ‘CPU time (ms)’ represents an MSM occupancy rate per minute, ‘NO taskswitching’ represents the number of times by which a relevant TASK is deprived of an occupation opportunity by other TASKs during an occupation time period and ‘Priority’ represents the priority of a relevant TASK. Herein, a larger priority number indicates a higher priority.
Referring to FIG. 2, it should be understood that the higher the priority is, the higher the MSM occupation rate becomes, resulting in a smaller number of switching times between TASKs.
According to a VOD service method of a conventional mobile station having the above-mentioned construction, after a mobile station accesses the VOD server through the WAP-based Internet, the MSM processes multimedia data up to the PPP layer, and then the multimedia processor processes the multimedia data from the IP layer to the RTP/RTCP/RTSP/HTTP layer. In this way, the conventional mobile station can process VOD data, which has been received from the VOD server through a wireless network, through the multimedia processor.
However, as shown in FIG. 2, the conventional mobile station must process data service (DS) and data protocol service (PS) having a considerably low priority such as ‘70’ and ‘60’ at the MSM thereof, so an overload is applied thereto, therefore, it is difficult to assure the maximum processing speed.